The first concerns the data released by Kobo that seems to suggest that the winner of the 2015 Bailey’s Prize, How To Be Both by Ali Smith, was only finished by 34% of readers. However, in print, readers would purchase one of two versions of the novel, each with the book’s two parts in alternate order. Yet someone from Apple told me that digital platforms include both versions, in which case the figure of 34% is highly misleading – and very unfair.

The second insight came from the Harrogate Festival’s amazing interview with screenwriter Paul Abbott. Asked how subscription channels such as HBO or Netflix affected the way he works, he said that Netflix’s policy was to commission work (presumably on the basis of their viewing data), hand over the money, and then not interfere until the drama or series was delivered. Get it wrong, and they’ll never use you again – fair enough. But presumably Netflix are confident enough of the winning combination of their data and the experience and track record of the talent they commission to stand back and not second-guess the creative process. Which supplies one possible answer to the question of what kind of expectations will be placed upon writers by the growing influence of data.

Screenwriter William Goldman is famous for saying of Hollywood that nobody knows anything. But that was before this kind of data meant that subscription channels do know certain kinds of things. If the Netflix approach becomes the working model for commissioning – in film, TV or fiction – then bring it on.

In honour of today’s launch House of Cards Season 3 on Netflix, this post is brought to you by Frank Underwood, a master of how to break the Fourth Wall and get away with it.

Kevin Spacey’s sly looks to camera (and of course those of the late Ian Richardson in the original BBC series), and his asides to us, the viewers, all add immensely to our appreciation of the character. It means that we, too, have directly experienced his charisma and been seduced by it.

House of Cards has proved that, on screen, breaking the Fourth Wall can deliver big results. But if the viewer is ever reminded that they’re merely looking at a TV set, then the magic is destroyed. Frank Underwood’s audacity lies not only in his invitation to collude but also in the huge risk he runs that our suspension of disbelief will be shattered, bringing the whole meta-fictional house of cards tumbling down: we feel what it’s like to walk that political tight-rope.

In prose fiction, a deliberately unreliable narrator can add suspense and mystery or, as in Wuthering Heights, a complexity of sympathy and interpretation. Get it wrong, however, and an unintentionally slippery point of view quickly induces queasiness in a reader.

Some writers creatively exploit the possibilities of a first-person narrative, others find it constricting, but either way it removes any confusion about what other characters know or might be thinking. In a third-person narrative, however, it’s all too easy to jump in and out of different characters’ heads, sometimes even between paragraphs, breaking the Fourth Wall and leaving the reader unable to settle down and identify with, or care about, any of them.

Point of view needs to be tightly patrolled. On screen, POV is constructed by who the camera is looking at while dialogue or action is happening, and can radically alter the meaning and intention of a scene. We identify most strongly with the person for whom there is something at stake. I think there’s a fundamental weakness in the opening episode of House of Cards Season 3, for example, (I saw it last night at the gala preview in London) because we share the POV of Doug Stamper far more viscerally than that of either POTUS or the First Lady.

That vital emotional investment in a character has to be there on the page, too. If a reader can effortlessly stay with a character, and get to know them by understanding what they notice and how they think – hopes, fears, self-delusions, denials and all – then they’ll be there, walking that tight-rope right along with them.